Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752650AbdFOTNs (ORCPT ); Thu, 15 Jun 2017 15:13:48 -0400 Received: from mail.kernel.org ([198.145.29.99]:52444 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752088AbdFOTJx (ORCPT ); Thu, 15 Jun 2017 15:09:53 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 81D72239C3 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=sstabellini@kernel.org From: Stefano Stabellini To: xen-devel@lists.xen.org Cc: linux-kernel@vger.kernel.org, sstabellini@kernel.org, jgross@suse.com, boris.ostrovsky@oracle.com, Stefano Stabellini Subject: [PATCH v4 06/18] xen/pvcalls: handle commands from the frontend Date: Thu, 15 Jun 2017 12:09:35 -0700 Message-Id: <1497553787-3709-6-git-send-email-sstabellini@kernel.org> X-Mailer: git-send-email 1.9.1 In-Reply-To: <1497553787-3709-1-git-send-email-sstabellini@kernel.org> References: <1497553787-3709-1-git-send-email-sstabellini@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 3729 Lines: 152 When the other end notifies us that there are commands to be read (pvcalls_back_event), wake up the backend thread to parse the command. The command ring works like most other Xen rings, so use the usual ring macros to read and write to it. The functions implementing the commands are empty stubs for now. Signed-off-by: Stefano Stabellini CC: boris.ostrovsky@oracle.com CC: jgross@suse.com --- drivers/xen/pvcalls-back.c | 119 +++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 119 insertions(+) diff --git a/drivers/xen/pvcalls-back.c b/drivers/xen/pvcalls-back.c index e4c2e46..437c2ad 100644 --- a/drivers/xen/pvcalls-back.c +++ b/drivers/xen/pvcalls-back.c @@ -51,12 +51,131 @@ struct pvcalls_fedata { struct work_struct register_work; }; +static int pvcalls_back_socket(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_connect(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_release(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_bind(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_listen(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_accept(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_poll(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + return 0; +} + +static int pvcalls_back_handle_cmd(struct xenbus_device *dev, + struct xen_pvcalls_request *req) +{ + int ret = 0; + + switch (req->cmd) { + case PVCALLS_SOCKET: + ret = pvcalls_back_socket(dev, req); + break; + case PVCALLS_CONNECT: + ret = pvcalls_back_connect(dev, req); + break; + case PVCALLS_RELEASE: + ret = pvcalls_back_release(dev, req); + break; + case PVCALLS_BIND: + ret = pvcalls_back_bind(dev, req); + break; + case PVCALLS_LISTEN: + ret = pvcalls_back_listen(dev, req); + break; + case PVCALLS_ACCEPT: + ret = pvcalls_back_accept(dev, req); + break; + case PVCALLS_POLL: + ret = pvcalls_back_poll(dev, req); + break; + default: + ret = -ENOTSUPP; + break; + } + return ret; +} + static void pvcalls_back_work(struct work_struct *work) { + struct pvcalls_fedata *fedata = container_of(work, + struct pvcalls_fedata, register_work); + int notify, notify_all = 0, more = 1; + struct xen_pvcalls_request req; + struct xenbus_device *dev = fedata->dev; + + while (more) { + while (RING_HAS_UNCONSUMED_REQUESTS(&fedata->ring)) { + RING_COPY_REQUEST(&fedata->ring, + fedata->ring.req_cons++, + &req); + + if (!pvcalls_back_handle_cmd(dev, &req)) { + RING_PUSH_RESPONSES_AND_CHECK_NOTIFY( + &fedata->ring, notify); + notify_all += notify; + } + } + + if (notify_all) + notify_remote_via_irq(fedata->irq); + + RING_FINAL_CHECK_FOR_REQUESTS(&fedata->ring, more); + } } static irqreturn_t pvcalls_back_event(int irq, void *dev_id) { + struct xenbus_device *dev = dev_id; + struct pvcalls_fedata *fedata = NULL; + + if (dev == NULL) + return IRQ_HANDLED; + + fedata = dev_get_drvdata(&dev->dev); + if (fedata == NULL) + return IRQ_HANDLED; + + /* + * TODO: a small theoretical race exists if we try to queue work + * after pvcalls_back_work checked for final requests and before + * it returns. The queuing will fail, and pvcalls_back_work + * won't do the work because it is about to return. In that + * case, we lose the notification. + */ + queue_work(fedata->wq, &fedata->register_work); + return IRQ_HANDLED; } -- 1.9.1